Posted by Brigham and Women's Hospital February 5, 2013

A sophisticated imaging system demonstrates cell division in an adult mammal heart.

As we age, our bodies lose the ability to make new heart cells, just at the time when we are most vulnerable to heart disease. According to the National Heart Lung and Blood Institute, the risk of heart disease increases for men over 45 years and for women over 55 years (or after menopause). Recent discoveries by researchers at Brigham and Women’s Hospital (BWH) about how new cardiac cells form may eventually help patients recover from heart disease by increasing the body’s ability to regenerate heart cells.

Though scientists know that the body can create new heart cells, they have been unsure about the process by which these cells are born and how frequently they are formed. By using a new method to image heart cells, the BWH research team, led by Dr. Richard T. Lee, Cardiovascular Division, and Dr. Claude P. Lechene, Department of Medicine, new light may be shed on the origin of new heart cells.

The BWH research team was able to observe the birth of new heart cells by tagging their genes so they would glow when viewed microscopically. The tagged heart cells were then observed using an imaging system known as multi-isotope imaging mass spectrometry (MIMS) to record the development of new heart muscle cells, known as cardiomyocytes, over several months.

Researchers were surprised to find that new heart muscle cells came primarily from existing heart muscle cells, even under conditions simulating a heart attack, when stem cells, part of the body’s internal repair system, are thought to be activated.

“Our data show that adult cardiomyocytes (heart muscle cells) are primarily responsible for the generation of new cardiomyocytes and that as we age, we lose some capacity to form new heart cells,” said Dr. Lee. This means that we are losing our potential to rebuild the heart in the latter of life, just when most heart disease hits us. If we can unravel why this occurs, we may be able to unleash some heart regeneration potential.”